Tamping roller



E. T. SMALL TAMPING ROLLER Y Nov. 5, 1946.-

Filed Aug. 2, 1940 2 Sheets-Sheet l BY fz/zdez'frf: imp; 1.

irrbz/vf rs E. T. SMALL TAMPING ROLLER Nov. 5, 1946.

2 Sheets-Sheet 2 Filed Aug. 2, 1940 INVENTOR. zi/zeirr BY g Q fTdE/VEXS.

Patented Nov. 5, 1946 OF ICE Everett 1. Small, Indianapolis, Ind., assignor to J. D. Adams Manufacturing Company, Indianapolis, Ind., a corporation of Indiana Application August 2, 1940, Serial No. 349,433

3 Claims.

" My invention relates to tamping rollers of the so-called "sheep's foot type. Among the objects of my invention are to produce a roller in which the tamping feet 'may be readily replaced when worn or when feet of a different size are desired, to provide for the relative angular adjustment of adjacent circumferential series of tamping feet, to provide a roller unit which can be used singly or combined with another unit, and to provide for the roller unit an improved drawbar which is adjustable so that the roller may be offset laterally relative to the pulling vehicle.

In carrying out my invention, I form each roller unit with a generally rectangular frame in which a hollow drum is journaled on a transverse axis. The tamping feet of the roller are mounted on an axially extending series of pairs of semicircular bands clamped to the outer surface of the drum. Each of the front and rear members of the rectangular frame in which the roller is located is provided centrally with a longitudinally projecting stud to either of which a draw-bar may be attached; or, if desired, these studs may be used to interconnect a pair of roller. units to a common draw-bar. When a single roller unit is being used, the connection between it and the associated draw-bar is such that the draw-bar may be disposed either perpendicular or at an angle to the roller-axis. .The tamping feet of the roller are so arranged as to minimize the possibility that they will pick up the soil over which the roller passes.

The accompanying drawings illustrate my invention: Fig. 1 is a side elevation of a single roller-unit with portions thereof broken away to show the construction more clearly; Fig. 2 is a plan view of a single roller-unit; Fig. 3 is a fragmental transverse section through the drum on an enlarged scale; Fig. 4 is a plan view illustrating how two of the roller units may be connected together to form a double roller; Fig. 5 is a vertical section on the line 55 of Fig. 4; and Figs. 6, '7, and 8 are related views illustrating the action of each tamping foot in compacting the soiL.

Each of the roller units embodies a generally rectangular frame having cross members in and longitudinally extending side members I l interconnecting the ends of=the cross members. Within the rectangular frame thus formed there is rotatably mounted a hollow cylindrical-drum l2 havingin one end wall an opening through which the drum may be filled with varying amounts of water or sand to control the effective weight of the roller. Such opening has associated with it a closure l3 which prevents loss of the drumcontents.

Mounted on the cylindrical surface of the drum are an axially extending series of pairs of semicircular bands'lli. The ends of these bands are turned outwardly to form ears I! (Fig. 3); and clamp bolts l8, extending between the adjacent ears of the two bands of each pair, clamp the bands firmly to the drum.

On each of the semi-circular bands Hi there is mounted a circumferentially extending series of tamping feet 20. These feet are of substantialy uniform thickness axially of the drum, but their circumferentially presented faces are concavely curved, as will be clear from Fig. 1, so that each foot, as viewed axially of the drum, will be wider atits ends than at its middle. In the preferred foot-shape, each side face of the foot corresponds substantially to a curve such as would be traced by a pointat ground level on a disk having a radius equal to the distance between the roller-axis and the outer end of the foot and rolling on a plane surface depressed below ground level by a distance equal to the radial extent of the foot. The narrowest portion of a foot so shaped will be located somewhat nearer to the inner end of the foot than to the outer end, and the radius of curvature of each side face will gradually increase from the inner end of the foot to'the outer end Desirably, the inner and outer ends of the foot are of approximately the same width.

Feet of the kind just described have an advantage in operation in that they do not tend to pick up the soil being rolled. Since the feet are of uniform thickness throughout their radial extent and are set in planes perpendicular to the roller axis, there is no tendency to pack the soil between the feet of different circumferential series. Owing to the above described shape of the side faces of the feet, each foot enters and leaves the ground cleanly without picking up any soil. The action of each individual foot is illustrated progressively in Figs. 6, 7, and 8, Fig. 6 showing a foot just, entering the ground, Fig. 7 a foot at its lowest point, and Fig. 8 a foot just leaving the ground. It will be clear from Fig. '7, that each foot, as it enters the ground, forms therein a depression having a rear face which,

when the foot reaches its lowermost point, will be spaced from the rear face of the foot as indicated at 2|. This space provides clearance for the outer rear corner of the foot as it leaves. the depression in the progression of the roller.- As a result, the outer rear corners of the feet do 3 not pick up any soil. of the foot imparts to the front face of the depression a conformation which will not be disturbed by the outer front corner of the foot as the latter leaves the depression. This is of material advantage, since it is the purpose of a tamping roller to compact the soil, and if the feet disturbedv the soil in their upward movement compaction of the soil would to'that extent be interfered with.

In order to prevent slipping of any pair of bands it upon the outer surface of the drum, the drum is provided in the plane of each pair of bands with diametrically opposite, outwardly projecting pins 25 adapted to enter holes 26 in the respective semi-circular bands. By providmg each band with a plurality of holes 26 spaced apart a distance equal to a fraction of the circumferential foot-spacing, it is possible to vary the extent to which the feet of the adjacent pairs of bands are staggered.

For the purpose of hauling the roller I provide each of the cross members H) with an outwardly projecting longitudinal stud 30 screwthreaded at its outer end. When a single-unit roller is to be used, a draw-bar 3| is attached to either of such studs through the medium of a block 32 which is received between and secured to two ears 33 at the rear end of the draw-bar and which is provided with a longitudinal opening for the reception of the stud 30. Anut 34 on the end of the stud 30 serves to hold the block 32 in place. Desirably, the block 32 is secured between the ears 32 by two bolts 35 which pass vertically through the block and ears on opposite sides of the stud-receiving hole in the block. The bolt-receiving holes in the block 32 and in the ears 33 are similarly staggered so that the drawbar and block may be secured together, as indicated in' full lines in Fig. 2, with the draw-bar in alinement with the stud-receiving hole in the block 32. By removing the bolts 35 and turning the draw-bar about its axis through 180 relative to the block 32, the bolts 35 may be re-inserted to hold the draw-bar at an angle to the stud-receiving hole in the block 32, as indicated by the dotted lines in Fig.2. With the block and drawbar so assembled, they may be rotated as a unit about the axis of the stud 30 to cause the drawbar to extend obliquely'forwardlw in either direction from the roller unit, thus making it possible to offset the roller unit laterally either to the right or to the left with respect to the hauling vehicle.

To prevent undue bending stress upon the stud 30, I may employ a brace 31 which extends obliquely between the draw-bar 3| and an end of the associated cross member Ill. The drawbar 31 may be provided with two longitudinally spaced holes 38 either of which may receive .9- screw passing through the forward end of the brace 31, so that the brace may be used irrespective of whether the draw-bar is in its normal or in an offset position. The rear end of the brace 31 may be secured to the cross member ill by a bolt 33.

For the purpose of preventing the accumulation of dirt between the bands IS on the drum. I may mount on each of the cross members it a series of drum-cleaning teeth 44. Desirably, each series of such teeth are secured to a plate 42, as by welding. and such plate is bolted to the lower surface of the associated cross member i0, one

Moreover, the front face 1 of the bolts employed conveniently serving as the bolt 39 by which the rear end of the brace 31 is secured to the cross member.

When it is desired to use two roller units together, I may employ the construction illustrated in Figs. 4 and 5. In this arrangement, two of the roller units are arranged coaxially and a T-shaped draw-bar 50 is employed, such draw-bar having at its rear and parallel bearings for the reception of the studs 30 at the front of the roller units. The studs 30 at the rear of the units are interconnected by a spacer 5| having at its ends parallel bearings in which the studs 30 are re- 'ceived.

With the double unit just described, each roller unit is free to oscillate about the common axis of its associated studs 30, as indicated in Fig. 5. I find it advantageous to limit the extent of this oscillation as by providing the draw-bar 50 with rearwardly projecting vertically spaced ears 53 which engage the front inner corners of the frame Ill-H of each roller unit and limit the extent to which that frame may oscillate about its associated studs 30 relative to the draw-bar 50.

The claims of this application are directed to the combination of the circumferentially extending bands IS with feet 20 of the shape described above. The feet alone form the subject matter of my co-pending application Serial No. 685,311 filed July 22, 1946.

I claim as my invention:

1. A tamping roller, comprising a cylindrical drum, an axial series of bands relatively angularly adjustable on said drum and releasably secured thereto, and a circumferentially extending series of tamping feet on each of said bands, each of said feet being at least as thick, axially of the roller, at its outer end as over the remaining portions of its radial extent and has circumferentially presented side faces which are concavely curved so that each foot is narrower near the middle of its radial extent than at its ends, the narrowest portion of each foot being located somewhat nearer to the inner end of the foot than to the outer end and the radius of curvature of said side faces gradually increasing from the inner end of the foot to the outer end.

2. A tamping roller, comprising a cylindrical drum, an axial series of bands relatively angularly adjustable on said drum and releasably secured thereto, and a circumferentially extending series of tamping feet on each of said bands, each of said feet being at least as thick, axially of the roller, at its outer end as over the remaining portions of its radial extent and has circumferentially presented side faces which are concavely curved so that each foot is narrower near the middle of its radial extent than at its ends, the narrowest portion of each foot being located somewhat nearer to the inner end of the foot a than to the outer end.

3. A tamping roller, comprising a cylindrical drum, an axial series of bands relatively angularly adjustable on said drum and releasably se cured thereto, and a circumferentially extending series of tamping feet on each of said bands, each of said feet being at least as thick, axially of the roller, at its outer end as over the remaining portions of its radial extent and has circumferentially presented side faces which are concavely curved so that each foot is narrower near the middle of its radial extent than at its ends.

EVERETT T. SMALL. 

